I found the definitive story behind this song, at least the Tarriers' version in the attached Erik Darling Obit. Lots of other interesting insights as well:

Erik Darling Dies at 74; Musician in the Weavers
By WILLIAM GRIMES
Published: August 7, 2008

Erik Darling, a preppy Ayn Rand devotee who replaced Pete Seeger in the Weavers and who was associated with two of folk music's biggest commercial hits, "The Banana Boat Song" and "Walk Right In," died Sunday in Chapel Hill, N.C. He was 74.


Erik Darling, far left, with Lynne Taylor and Bill Svanoe in 1963.
The cause was lymphoma, said Allan Shaw, president of Folk Era/Wind River Records, for which Mr. Darling had made albums in recent years.
A virtuoso guitarist and banjo player, Mr. Darling performed with two of the leading folk groups of the day, the Tarriers and the Weavers, which he joined after Mr. Seeger left in 1958.
Mr. Darling "was the first guitar gunslinger I came across," said the singer and songwriter Don McLean, who befriended him in the early 1960s. "He practiced endlessly, and he got a beautiful sound out of his guitar and his banjo. Today you see any number of fabulous guitar players, but back then there were only a handful, and he was one."
Erik Darling was born in Baltimore and grew up in Canandaigua, in the Finger Lakes region of New York, where his father ran a paint business. His interest in folk music was sparked when the Sons of the Pioneers came to town for a concert.
After his parents divorced, he lived with his mother in New York City, where he attended the Rhodes Preparatory School.
"One New York Sunday I took a double-decker Fifth Avenue bus down to Washington Square, where I had been told people sang folk songs," he once wrote. At the time he knew only a few basic guitar chords. "I didn't dare play that first day, but I became part of that crowd and did not miss a Sunday for years," he wrote.
He improved. Later, when he was not performing and recording with his own groups, Mr. Darling played backup on recording sessions for artists like Ramblin' Jack Elliott, Oscar Brand, Jean Ritchie and Judy Collins.
In the early 1950s Roger Sprung, a banjo player prominent on the folk scene, invited Mr. Darling and Bob Carey to form the Folksay Trio, which recorded four songs, including "Tom Dooley," for the tiny Stinson label. Their syncopated interpretation of the song, which introduced a signature pause, or hiccup, between the words Tom and Dooley, strongly influenced the Kingston Trio when that group recorded the song.
After Mr. Darling's next group, the Tunetellers, disbanded, he and Mr. Carey formed the Tarriers, a trio that searched desperately for a stable third member until a young actor named Alan Arkin agreed to leave Los Angeles and join the group, which soon scored a Top 10 hit with "Cindy, Oh Cindy."
In 1956 the Tarriers (once billed as a dog act called the Terriers by a confused promoter) adapted a traditional work song that the folk singer Bob Gibson had heard in Jamaica and brought to Washington Square. After fusing it with another Jamaican song called "Hill and Gully Rider," they recorded it for Glory Records as "The Banana Boat Song" and watched in amazement as it climbed the pop charts and set off a craze for calypso music, fueled in part by Harry Belafonte's reworked version of their song, "Day-O."
The Tarriers, swept along by the calypso tide, appeared in the film "Calypso Heat Wave," whose performers included Maya Angelou. "Every time we appeared on a TV show, the set was palm trees and bananas, or pilings, barrels and docks, or all five," Mr. Darling once wrote.
When Mr. Seeger left the Weavers, Mr. Darling replaced him, initially on a trial basis as the group rushed to complete a half-finished album. He stayed for four and a half years as the group evolved into a genuine quartet rather than a trio appended to Mr. Seeger.
"He had an interesting voice rather than a beautiful voice," Mr. Shaw said of Mr. Darling. "But he was a superb instrumentalist and arranger."
Mr. McLean said: "Erik brought new energy and new harmonies to the group. He was good for them, and they were good for him."
His voice blended better than his libertarian politics, however, which eventually created friction.
In 1962 Mr. Darling formed the Rooftop Singers specifically to update "Walk Right In," originally recorded by Cannon's Jug Stompers in the 1920s but rearranged by Mr. Darling with twin 12-string guitars, played in a pounding, percussive style. The song became a No. 1 hit and created a fad for 12-string guitars.
The Rooftop Singers disbanded in 1967, and Mr. Darling, after recording a duet album with Pat Street, a replacement vocalist for the Rooftop Singers, drifted away from the music business for many years.
In 1994 he recorded "Border Town at Midnight" for Folk Era, a collection of western-tinged songs that reflected his new home, Santa Fe, N.M. In 2000 he recorded a concept album, "Child, Child," devoted to what he called "the most vital issue of our time — the thoughtful raising of children."
Mr. Darling is survived by his former wife, Joan, of Chapel Hill. Shortly before his death he completed an autobiography, "I'd Give My Life!: A Journey by Folk Music" (Science and Behavior Books).
Mr. Darling "brought folk music to people who had never heard it before," said Richie Unterberger, an author of several books on the genre. "It might not have been the rootsiest folk music, but it was very enjoyable to listen to."